Process of making nitrogen compounds.



UNITED s'rxrns PATENT carton...

OSCAR FREDRIK OARLSON, OF STOCKHOLM, SWEDEN.

' EROCESS OF MAKING NITROGEN COMPOUNDS.

To all whom it may concern;- Be it known that I, OSCAR FREDRIK CARL-so.\'. a subject of the King of Sweden, and resident of Kornhamnstorg i,Stockholm, in the Kingdom of Sweden, have invented certain new anduseful Improvements in Processes of Making Nitrogen Compounds, of whichthe following is a specification.

This invention relates to certain improvements in the art of producingnitrogenous compounds, and more particularly 1n the artificialproduction of nitrogenous compounds-such as are especially adapted foruse as fertilizers, and the object of the invention is, in part, toimprove and simplify the production of such compounds whereby certaineconomic advantages are attained in the manufacture thereof and, inpart, to provide a compound of this character of a novel andcomparatively inexpensive nature which shall atlord certain importantadvantages for use, all as will be hereinafter fully set forth.

The novel features of the invention will be carefully defined in theclaims.

It is well known that nitrogen gas, when passed over a carbid of analkaline earth metal, is absorbed with production of a nitrogenouscompound which is well suited for use as a fertilizer. Where calciumearbid is employed in this manner, the resultant product consists ofcalcium-cyanamid and carbon, and where barium carbid is employed, theresultant product consists of barium-cyanamid, barium carbid, bariumcyanid and carbon. The commercial calcium carbid has been considered tobe most suitable for employment in this manner, and in order to carryout the reaction upon an industrial scale without the addition of anyother material, it has been found necessary to subject the calciumcarbidtoa tem era- -ture of from about 1100C. to 1200 in order to secure goodresults, but this high temperature has occasioned great difliculty inthe carrying out of the process, and has rendered the same so expensivethat it is not well suited for practical utilization. For this reasonattempts have been made to carry out the reaction at lower temperaturesby the addition of chlorid of calcium, or a clorid of some otheralkaline earth, or of an alkali metal, and in this way valuabletechnical results have been attained, whereby the artificial productionof nitrogenous compounds is rendered much more practical andSpecification of Letters Patent.

' Application filed July 19, 1906.. Serial No. 326,841.

Patented'Nov. 10, 1-908.

economical. But when these mixtures are employed a considerableproportion of calcium chlorid will be present in the product, and agreat disadvantage has been encountered by reason of the hygroscopicnature of this compound, which caused the finished product to accumulatemoisture to such a degree as to prevent it from being readily applied tothe ground for use, and results in the bursting of sacks, etc., duringstorage of the product.

According to my i calcium carbid a suitable percentage of a fluorid ofan alkali or alkaline earth metal, or a plurality of fluorids, and theresulting mixture, on being subjected to a temperature of from about 700C. upwards, is capable of absorbing a comparatively great percentage ofnitrogen gas. Furthermore such absorption is more rapidly effected wherethe process is conducted with the addition of one or more fluoridsaccording to my invention.

In carrying out my invention in practice, I have found that an admixtureof from per cent. upwards to 30 per cent. of fiuor spar with the calciumcarbid gives excellent results, but I prefer to employ from 2 to 5 percent. of this substance, and in respect of the temperature I prefer totake advantage of the exothermic nature of the reaction and to soconduct the process that the material is subjected to a temperature offrom about 800 to 900 C., which temperature is attained in part by theexterior heating, and in part by the heat developed by the reactionbetween the nitrogen and the carbid of calcium. Through this range oftemperature the absorption of nitrogen is very energetic and complete,so much so that almost the full volume of nitrogen which can betheoretically taken up by the calcium carbid to transform it intocalcium-cyanamid, is absorbed in a comparatively short time.Ifdesirable, a similar result may be attained by heating the mixture ofcarbid and fluorid to a lower temperature than 700 (1., and heating thenitrogen to a higher temperature, say 1000 to 1200 0., and bringing thenitrogen, while thus heated, in contact with the mixture, whereupon thetemperature at the surface of nvention I add to the the mixture willsoon rise above 7 00 C., and p the reaction will commence, developing aconsiderable heat which will aid in maintaining the reaction.

It may be stated that in carrying out my improved process no result ofpractical importance can ordinarily be attained Where the reaction isconducted at a temperature less than 700 C.

In order to insure the best results, the materials should, of course, beproperly ground and mixed. '1 take for example, an admixture of 3 partsof fluor spar with 97 parts of calcium carbid and lead the nitrogen overthe same, meanwhile employing sufficient external heat to maintain suchmixture at a temperature of 750 C. Such external heating will besufficient to bring about the commencelnent of the reaction, and duringthe continuance of the reaction sufiicient heat will be developed by itsexothermic nature to raise the temperature of the mixture to about 900C. By this procedure products are obtained containing as much as 23 percent. of nitrogen. The percentage of nitrogen contained in the finishedproduct will, however, be dependent upon the percentage of CaC containedin the particular specimen of commercial calcium carbid employed. Theresultant product manufactured accord ing to my invention is especiallydesirable for use by'reason of the high percentage of nitrogen containedin it, and also by reason of the elimination of the hygroscopicproperties possessed by the products resulting where calcium chlorid isemployed, since there is no difliculty encountered either in storing orspreading the improved fertilizer compound, nor any tendency toexcessive loss of the fertilizer after the same has been spread upon theground, due to too ready solubility.

Owing to the general similarity of properties existing between thecompounds of alkaline earth metals and of alkali metals, it will beapparent to those skilled in the art that in my improved process thefiuorids of the metals of the one group may usually be substituted forthe corresponding compounds of the other group without departure from 1the principles and spirit of the invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent 1s 1. The herein described process of producingnitrogenous compounds which consists in exposing a mixture of a carbidof an alkaline earth metal with a fluorid to the action of nitrogen gasunder circumstances such that the nitrogen\ and the mixture are broughtinto contact with each other at or above a temperature of about 7 00 C.

2. The herein described process of producing nitrogenous compounds,which consists in subjecting a mixture of a carbid of an alkaline earthmetal and a fiuorid to a temperature of not less than 700 C. in presenceof nitrogen gas.

3. The herein described process of producing nitrogenous compounds whichconsists in exposing a mixture of calcium carbid with a fluorid to theaction of nitrogen gas under circumstances such that the nitrogen andthe mixture are brought in contact with each other at or above atemperature of about 700 C.

4. The herein described process of producing nitrogenous compounds whichconsists in exposing a mixture of calcium fluorid with a carbid of analkaline earth metal to the action of nitrogen gas under circumstancessuch that the nitrogen and the mixture are brought in contact with eachother at or above a temperature of about 700 C.

5. The herein described process of producing nitrogenous compounds whichconsists in exposing a mixture of the carbid of an alkaline earth metalwith the fluorid of an alkaline earth metal to the action of nitrogengas under circumstances such that the nitrogen and the mixture arebrought in contact with each other at or above a temperature of about 700 C.

6. The herein described process of producing nitrogenous compounds whichconsists in exposing a mixturev of calcium carbid with calcium fi uoridto the action of nitrogen gas under circumstances such that the nitrogenand the mixture are brought in contact with each other at or above atemperature of about 7 00 C.

In witness whereof I have hereunto signed my name this 3 day of July1906, in the presence of two subscribing witnesses.

OSCAR FREDRIK GARLSON.

Witnesses CARL TRIBEY, .AXEL EIIRNER.

